I’ve never really thought about it. All I’ve ever heard is you should achieve a vigorous, rolling boil. But is there such a thing as too hot of a boil? My last boil made me think it was actually TOO aggressive. I lost 2.5 gallons from pre-boil to fermentor.
Anyway, any insight is appreciated.
Cheers!
My 2 cents.
When we boil we basically do 2 things.
Sanitize and concentrate.
212 degrees F for 15 minutes will sanitize your wort. When we boil longer we are looking for a certain volume and SG.
If you add IBU into the picture then hop bitterness come into play.
I would think if the temp is too hot you could burn your wort. I’ve never heard of it but i bet it could happen and possibly cause an acrid flavor.
If the surface of the wort is bubbling then you’re good enough. I would say a solid simmer is plenty of boil vigor.
Thermal stress is placed on wort, more heavily so on long, excessively turbulent boils, resulting in excessive darkening of wort and may well impact malt flavor. Where advice used to be to target 10-15% evaporation, well under 10% evaporation may well ward off these effects. FWIW I get 7-8% evaporation.
Edit - http://www.lowoxygenbrewing.com/uncategorized/low-oxygen-boiling/
I’ve read that a good boil really looks more like a simmer vs a volcano.
+1 - though I will say that it doesn’t really matter except for your evaporation rate calculation 9and possible scortching if it gets insanely hot). You really can’t boil too hard. The boil won’t get hotter than 212 (depending on your elevation obviously). A gentle roiling boil will give you everything you need and save you gas and from having to top off with water at the end. On my 14 gallon kettle I can get the wort about a half inch from the top of the kettle and boil for 90 minutes without having a boil over (well, mostly.) Just got to gently feather that gas regulator.
Most homebrewers boil off far too much simply due to small volumes and (relatively) large burners. Just how much boiloff is necessary is system-dependent (elevation, kettle geometry, calandria vs. natural convection vs. recirculation, etc.) but 5-10% is definitely all that’s needed to volatilize DMS. FWIW, I boil off ~12% on my 6 gal batches because that’s the lowest I can throttle my burner while still getting a clean flame.
A longer or more vigorous boil can be desirable in certain situations where the Maillard products are essential to the beer (doppelbock e.g.), but boiling off 2.5 gal in a 5-10 gal batch is probably just wasting fuel.
In regards to the maillard products.
I can pick up some of these characteristics in many commercial and tons of homebrewed beer. When I went to low oxygen brewing I picked it up in my own quite glaringly. That’s why I took measures to reduce TBI. Worked wonders.
I was glad all this came up a ways back. I had always heard DMS drama. I boiled my ass off. My rig burner design could send boil over into the next county. My current Kolsch was the first low burn/evap conscious brew. It is cleaner in flavor, plus I ended with 21 gallons in my 25 gallon kettle. Do temps matter, I’ll say yes they do. Give me 5 brews to decide, but I can tell…I think.
I agree with you that most homebrewers “overboil”, but serious question here, do you take every piece of 20th century German literature as gospel?
Lol [emoji23] I quoted “American” literature here.
But to answer your “serious” question the literature I quote is teaching material at the brewing schools. To top that off Kunze was updated in 2015 if I am not mistaken [emoji6]. So are you calling schooled brewers with degrees and phd’s foolish for their coursework? Do you have recommendations for more current works?
I said I agreed with you bud. And a lot of stuff is taught in a lot of schools. Should it all be taken at face value?
When backed by empirical and repeatable data, yes. At least until new data proves otherwise.
Couldn’t agree more, this is a big reason why I don’t buy into all this homebrewers scale lodo stuff.
I think you missed Stevie’s point.
I honestly believe most of the Low Oxygen stuff is legit. I have worked some of it into my process, but I have too many other limitations to adopt it and test fully. For some the change in process may not be worth it, but that doesn’t mean it’s bunk.
Is there empirical evidence that showing that it doesn’t matter at the homebrew scale? Sure lots of preferential and anecdotal evidence, but I haven’t seen numbers against it.
Yeah. I get that things like autolysis aren’t as big an issue as quickly at home because we only have a small fraction of the pressure on our yeast as Keith does at Yellowhammer. But as for oxidation, how could it not be a legit concern at home? The same oxidating air exists in the home as well as at a brewery. I’ve done a few batches now, and IMO oxidation/lodo is absolutely legit. I have 2 young Dunkels at just over 3 weeks now and the difference is stark. In a couple weeks when the beers are crystal clear, I’ll do the triangle to see what others say.
Look forward to the results of that Jon.
I don’t doubt that low dissolved oxygen brewing is generally a good thing. But, I would like to see a triangle test to see if the average drinker can taste the difference between brewer with a low dissolved oxygen process and home brewed beer with a more typical amount of dissolved oxygen during brewing.
I brew 3 gallon batches that last 3-5 weeks in the keg. If the primary benefit of a low dissolved oxygen process is shelf life then maybe I don’t need to bother.